The impetus is a natural turn with a heel turn for the man. With balance check, mistake list and practice path – exact footwork is up to your teacher.
The honest answer to “What is the impetus?”: It is a natural turn in slow waltz into which the man builds a heel turn. In a heel turn you pivot on the heel of the standing foot while the other foot closes in. “Impetus” means momentum – and that is what you feel: the turn gains pull without you getting faster.
Why this figure costs nerves: for a moment you turn on a small support point while the lady continues her path (your teacher shows exactly how). Errors in weight and alignment show immediately. That turning on one leg is a matter of practice is shown by research from ballet: beginners swayed their centre of mass over the pressure point on the floor much more in the preparation and the ending of the pirouette, overshot in the preparation and kept correcting at the end [1] (TRANSFER: ballet, not waltz). For you that means: preparation and run-out are where you gain the most.
In a waltz spin of a world champion couple the man started the movement at the pelvis, the woman at the ribcage [2] (TRANSFER, one couple only – a hint, not proof).
Realistic: You understand the principle in one evening. Security on the heel grows over weeks (experience value).
What the figure brings to your dancing: it adds variety and dynamics to a long sequence of natural turns. In slow waltz the accent lies on count one; the heel turn uses exactly this accent to build momentum and then runs out softly (practice experience, no study evidence). Whoever does it cleanly looks calmer when dancing – even when the music is fast.
Dance the natural turn twice in a chain. Milestone: The head stays at the same height, no bobbing.
Stand with one foot forward at a barre or a chair. Turn on the heel of the standing foot while the other foot closes in. The weight rolls from heel to ball. Milestone: You turn without hopping and stand calmly afterwards.
From the ballet study you know: most unrest happens before and after [1]. So practise only the entry and the run-out – two bars each, without the turn in between. Milestone: You stand still for two counts after the run-out.
Natural turn up to the heel turn, then continue. Say the counts aloud. Milestone: You hit the count without over-rotating.
The man leads the heel turn early through the torso, the lady stays in the hold and finishes the outside path. Milestone: Your partner says she never had to “pull”.
In the impetus you turn on a small area: a slippery floor or soles that grip too much can twist the knee and ankle. In a Dutch survey 80.7 % of competitive dancers had at least one injury, most often at the foot, ankle and lower leg [3]. Warm up, practise on a suitable floor and have your technique checked by a teacher. This guide explains and motivates; it does not replace supervised training.
Do the heel turn in front of a door frame: if your shoulder or hip brushes the frame while turning, you see at once that you are pushing yourself off-centre. This is a practice trick, not a study finding.
A second trick against hopping: put a thin towel under the standing foot and turn on it. If it slides along, you shifted the weight too far forward. The towel gives honest feedback without anyone standing next to you (practice trick). Do this only on a smooth, level floor and never in socks on tiles.
Your weekly plan (practice suggestion): Three sessions of 15 minutes. Session 1: heel turn solo, clockwise and anticlockwise. Session 2: entry and run-out. Session 3: complete figure, video from behind.
Video check in three points: (1) Does the head line stay calm? (2) Do you stand still after the run-out? (3) Does the lady travel without a pull?
A natural turn in slow waltz in which the man performs a heel turn. The name means momentum. The exact footwork depends on the syllabus; ask your teacher.
A turn on the heel of the standing foot while the other foot closes in. The weight rolls from heel to ball. It is a basic technique in standard dancing.
Beginners sway more in the preparation and at the end than experienced dancers [1] (ballet). So practise entry and run-out deliberately and keep the head line calm.
Slower than the music. The turn comes from the centre, not from tempo.
Telemark in Slow Waltz: Left Turn With a Heel Turn for the Lady